Some leaf die-off is common to clones. The important thing to remember is to mist the enviornment, not the plant. If it has roots, avoid overwatering and 'harden' them up to an un-domed enviornment. Plants do not acclimate overnight. Remove dome for a few hours at a time for a few days, then remove it entirely. (but keep an eye on 'em)

Old leaves are old news. Is there new growth starting to show?

Did you add nutrients at all? (foliar feeding an unrooted clone is a no-no)

Look around the growlog section for cloning procedures, or look in the FAQ section. (there is a search function for this website, )